By way of background, as demand continues for high capacity distributed data centers, virtualization technologies, including the use of virtual machines and software defined networking, have been leveraged to provide increased scalability and enhanced performance of network and computer resources. For instance, virtualization of resources, such as network, computer, and storage resources, allows abstraction of physical resources into logical representations, providing for flexibility in the provisioning and management of services and hardware infrastructure. In addition, virtualization can enable the deployment of multi-tenant data center infrastructures, in which multiple independent customer domains can be hosted using a single set of physical resources. In addition, virtualization can allow for virtual machines, such as virtual servers or clients, to be deployed with variable levels of computer resources, which can be increased or decreased as needed. Further, virtualization can allow for virtual machines to be migrated from one location to another location. In particular, in one example, a virtual machine can be migrated from one data center to another data center, for example, to allow for maintenance of the one data center without interrupting client sessions with the virtual machine. In another example, a virtual machine can be migrated from one physical server to another physical server within a data center, in order to provide increased resources needed by the virtual machine during a time period in which the volume of client network traffic or client demand for virtual machine processing resources increases.
However, some of the features that make virtualization technologies attractive can lead to problems, because underlying physical resources, such as computers and network devices, can be harder to manage and track when services and software are virtualized, because the physical locations are decoupled from the virtual locations. For example, networks and applications designed to operate in a single geographically centralized data center can behave differently when their components are spread across a geographically diverse virtual environment. In such a case, technological issues can arise with the computer technologies, such as loss or delay of network or server traffic.
In one particular example, underlying networking technologies, such as Transmission Control Protocol/Internet Protocol (TCP/IP), include features by which a client/server session may be restored after interruption, such as the migration of the server from one network location to another network location. For example, a timeout window, which may be on the order of minutes, is typically set. In such a case, if clients fail to receive responses from the server within the timeout window, each client can abort its TCP/IP session and initiate a new TCP/IP session to the server. Because TCP/IP technology does not contemplate the relocation of a server from one network to another network, this timeout window simply leads to disconnection of each and every single client of the server, followed by a mass attempt for each client to reconnect to the server. Meanwhile, all state information maintained by the server for the client has been lost, and business transactions that were previously in progress have been terminated. Therefore, a need exists for technological solutions to enhance and improve the functioning of virtualized technologies when, for example, virtual machines are migrated over a software defined network.